Effects of intensive diabetes therapy on neuropsychological function in adults in the Diabetes Control and Complications Trial

Ann Intern Med. 1996 Feb 15;124(4):379-88. doi: 10.7326/0003-4819-124-4-199602150-00001.


Objective: To examine the effect of intensive therapy on neuropsychological performance in patients who participated in the Diabetes Control and Complications Trial (DCCT).

Design: Multicenter, randomized, controlled clinical trial.

Setting: 29 DCCT clinical centers.

Patients: 1441 patients with insulin-dependent diabetes mellitus (IDDM) between 13 and 39 years of age who had had IDDM for 1 to 15 years and had no or minimal retinopathy or nephropathy at baseline. Volunteers were excluded if they had a history of substance abuse, psychological disturbance, or recurrent hypoglycemia with coma or seizure.

Intervention: Intensive therapy with 3 or more daily insulin injections or continuous subcutaneous insulin infusion, guided by 4 or more glucose tests per day, compared with conventional therapy with 1 or 2 daily insulin injections.

Outcome measures: Neuropsychological assessments were done at baseline; years 2, 5, and 7; and the end of the study. Eight cognitive domain scores were developed from the test results and were used to identify patients whose neuropsychological performance had clinically worsened.

Results: Intensive therapy did not affect neuropsychological performance. In addition, patients who had repeated episodes of hypoglycemia did not perform differently than patients who did not have repeated episodes.

Conclusion: Intensive therapy and the attendant risk for hypoglycemia were not associated with neuropsychological impairment in the DCCT.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Cognition Disorders / etiology*
  • Diabetes Mellitus, Type 1 / complications
  • Diabetes Mellitus, Type 1 / drug therapy*
  • Diabetes Mellitus, Type 1 / psychology*
  • Drug Administration Schedule
  • Female
  • Follow-Up Studies
  • Humans
  • Hypoglycemia / etiology
  • Infusion Pumps
  • Injections
  • Insulin / administration & dosage*
  • Male
  • Neuropsychological Tests
  • Patient Compliance
  • Regression Analysis


  • Insulin